Flat warp knitting machines

ABSTRACT

A flat warp knitting machine comprising two continuously driven endless transport chains provided with hooks, weft thread laying means, means for moving the weft thread laying means back and forth transversely to the transport chains for inserting weft threads alternately into the hooks of the two transport chains and means for moving the weft thread laying means at least partially in the direction of motion of the transport chains for the insertion of the weft threads into at least approximately opposite pairs of hooks so that the weft threads extend at least approximately at right angles to the transport chains.

United States Patent 1151 3,665,732

Doring et al. [451 May 30, 1972 541 FLAT WARP KNITTING MACHINES 1,661,055 2/1928 Springthorpe ..66/84 [72] Inventors: Wolfgang Doring, Crimmitschau; Bertram glisersberger Freud Kafl Marx smdt; Hans meter 2 a 6 Heutschel KarLMaIXSmdt; Heinz 3,523,43 8/1970 Va da et 6/125 Kemter, KarLMaIXStadt; Werner 3,564,872 2/ l 971 Klaevi ..66/85 Mickenautsch, Crimmitschau ll; Harry Schmidt werdau, an of Gama), Primary Examiner-Ronald Feldbaum Attorney-Nolte and Nolte [73] Assignee: VEB Wirkmaschinenbau Karl-Marx-Stadt,

Karl-Marx-Stadt, Germany [57] ABSTRACT [22] Filed: 1970 A flat warp knitting machine comprising two continuously driven endless transport chains provided with hooks, weft thread laying means, means for moving the weft thread laying means back and forth transversely to the transport chains for 21 Appl. No.: 61,596

[52] U.S. Cl. ..66/84,28/1 CL inserting weft threads alternately into the hooks of the two transport Chains and means for moving the f thread yi g 1 o a 2 means at least partially in the direction of motion of the trans- 28/1 CL port chains for the insertion of the weft threads into at least approximately opposite pairs of hooks so that the weft threads [56] Reierences cued extend at least approximately at right angles to the transport UNITED STATES PATENTS chajns- 3,446,038 5/1969 Inui ..66/84 17 Claims, 14 Drawing Figures .J. 1. "'A'AAA A v n A Patented" May'3f7, 1972 1O Sheets-Sheet 1 Patented May 30, 1972 10 Shuts-Sheet I Patented May 30, 1972 10 Sheets-Sheet 5 Patented May 30, 1972 3,665,732

10 Sheets-Sheet 4 Patented May 30, 1912 10 Sheets-Sheet 6 Illhl'lali LITIILII IL llllrrlllll Patented May 30, 1912 3,665,732

10 Sheets-Sheet 8 Patented May 30, 1972 3,665,732

10 Sheets-Sheet 9 Patented May 30, 1912 3,665,732

10 Sheets-Sheet l0 FLAT WARP KNITTING MACHINES The invention relates to aflat warp knitting machine, in particular, a sewing knitting machine which for the production of a textile material having weft yarns is provided with two continuously driven endless transport chains equipped with hooks as well as with a weft yarn laying device movable back and forth crosswise to the transport chains, the weft yarns being inserted by means of the weft yarn laying device in the hooks of the two transport chains and by means of them being fed to the stitch forming point.

A known warp knitting machine, in particular a sewing knitting machine of this kind (German Pat. No. 1,059,608), serves to produce a weft-warp knit fabric, of which the weft yarns represent the ground material, which is bound in between the sinker and needle stitches of the warp knit fabric. With respect to the means serving to grip the preparatorily laid weft yarns and to bring them to the stitch-forming point, this machine is outstanding for its particular simplicity. The two transport chains having hooks merely need a very simple epicyclic gear, and to this, moreover, a part of the high efficiency of this machine is attributable. Because of the continuous drive of the transport chains, however, the weft yarns can be gripped only in the form of overlapping zig-zag weft thread layers, thus resulting in a weft-warp knit fabric in which the weft yarns extend obliquely to the longitudinal axis of the material and hence also obliquely to the stitch rows. At variance therewith, in classic weft-warp knit fabrics the weft yarns run exactly parallel to the stitch rows.

Weft-warp knit fabrics are practically without transverse stretchability. If they are furthermore equipped with stretched longitudinal warp yarns, such warp knits practically attain the dimensional stability of woven fabrics. The classic weft-warp knit fabrics resemble woven fabrics also in theirweave-like pattern, although because of the oblique weft yarns this does not apply to weft-warp knit fabrics made on the above described machine.

It is an object of the invention to provide a warp knitting machine, in particular a sewing knitting machine, of the kind mentioned initially, on which can be produced fabrics the weft threads of which, following the pattern of woven fabrics extend at right angles to the longitudinal axis of the fabric and hence parallel to the stitch rows.

This problem is solved according to the invention in that the weft thread laying device, for the insertion of the weft yarns into two hooks facing each other in a line extending at least approximately at right angles to the transport chains, is movable at the same time crosswise to its fundamental movement. By means of the invention it is not only possible to produce outright weft-warp knit fabrics in which the weft yarns are functionally the ground material. It is possible also to produce textile fabrics in which the wefts serve purely a pattern forming function. In this case there may serve as the ground material, for example, a fiber mat to which the pattern weft threads are tied by means of a warp knit fabric consisting of individual wales. Such a machine is evident in principle from British Pat. No. 552,754, although there the weft yarns are not directed at right angles to the longitudinal axis of the fabric and also are not pattern threads. The weft yarns of the textile fabric produced on the machine of this patent can, therefore, also be bound into the fabric at right angles to the longitudinal axis of the fabric by means of the invention.

Furthermore, it is feasible according to the invention to provide a weft-warp knit fabric the ground material of which consists of overlapping, zig-zag weft yarn layers with pattern weft yarns which extend parallel to the stitch rows and hence at right angles to the longitudinal axis of the fabric. Such an embodiment of the invention is characterized in that there are at least two weft thread laying devices, of which only one is movable back and forth crosswise to its fundamental movement.

The invention will now be further described by reference to specific embodiments thereof as illustrated in the drawings, in which:

FIG. 1 is an isometric view of a weft yarn laying device movable crosswise to the transport chains as well as crosswise to this fundamental movement, the laying device being provided for the drive in the last-named direction with a cross-bar which at its ends is in articulated connection with two codirectional rocker arms driven by a cam plate;

FIG. 2 is an isometric view of a similar weft yam laying device, but with two endless chains being provided for the drive of the cross bar;

FIG. 3 is an isometric view of a weft yarn laying device likewise provided with a cross bar for the drive crosswise to its fundamental movement, which cross-bar can be set in pivotal movement by means of a cam plate;

FIG. 4 is an isometric view of a similar weft yarn laying device provided with a pivotally movable cross-bar which can be driven hydraulically;

FIG. 5 is a schematic diagram of the hydraulic drive by itself;

FIG. 6 is an isometric view of the two weft yarn transport chains onto which both ground and pattern weft yarns are hooked;

FIG. 7 is a plan view of a double weft yarn laying device for obtaining weft yarn layers according to FIG. 6;

FIG. 8 is a side elevation view of the pattern weft yarn laying device of FIG. 7 by itself;

FIG. 9 is a sectional view of the pattern weft thread laying device taken on section line IX-IX of FIG. 8;

FIG. 10 is an isometric view of another double weft yarn laying device, in which the pattern weft yarn laying device, at variance with FIG. 7, has its own drive crosswise to the endless transport chains;

FIG. 11 is an isometric view of the pattern weft yarn laying device of FIG. 10 by'itself;

FIG. 12 is a plan view of a ground weft yarn laying device equipped with two pattern weft yarn laying devices;

FIG. 13 is a plan view of the back (left side) of a knit fabric produced with the weft thread laying device of FIG. 12', and

FIG. 14 is a plan view of the front (right side) of the same weft-warp knit fabric.

The present warp knitting machine, in particular sewing knitting machine, is provided, as is known and therefore not shown, with a knitting needle row and at least one laying rail for providing the knitting needles with warp yarns. From these warp yarns the knitting needles form, for example, a closed fabric (FIGS. 13 and 14).

Between the needle stitches 56 and the sinker stitches 81 of the warp fabric there are to be bound in, on the present machine, weft yarns 13 directed parallel with the stitch rows, which yarns serve as, for example, the ground material of a weft-warp knit fabric or serve to pattern a textile fabric which likewise consists of a warp knit fabric but may alternatively consist of a fiber mat, a woven fabric or the like.

In a manner also known in itself, the weft yarns 13 are inserted behind the stitch forming point of the machine into the hooks of two endless transport chains 1 and 2 (FIG. 6), for which purpose for example, the weft thread laying device 3 shown in FIGS. 1 to 4 is used. It comprises in this case two end plates 4 and 5 arranged one behind the other, which are connected together by rods 6, and a slide 7 guided on the rods 6. The weft thread laying device 3 itself is guided on fixed rods 8 and 9 extending at right angles to the transport chains 1 and 2 and for which the plates 4 and 5 are provided with guide rolls 10. To the front plate 5 a chain 11 is connected, by means of which the weft yarn laying device 3 is moved back and forth crosswise to the transport chains 1 and 2, this representing the fundamental movement thereof. The rods 6 are directed at right angles to the bars 8 and 9, so that slide 7 of the weft yarn laying device 3 can be moved also crosswise to its fundamental movement. Slide 7 is provided with an eyelet strip 12 the eyelets of which guide the weft yarns 13. To slide 7 there is connected according to FIG. 1 a cross-bar 14, the ends of which are articulated to two levers 15. The levers 15 are codirectional and can be pivoted toward the stitch forming point of the machine and back and are held in the forward end position by means of springs 16. Connected to the levers at a point spaced from the pivot point of each are cables 17 which are guided over rolls and are connected at their other end to a lever 18. The latter cooperates with a cam plate 19, which is connected fixedly to a continuously rotating sprocket 20. From the latter there may be derived at the same time also the drive of chain 1 1.

As stated above, it is intended by the invention to bind the weft yarns 13 parallel to the stitch rows of the warp knit fabric, that is, at right angles to the longitudinal axis of the fabric. For this purpose, the weft yarns 13, which in the case of FIGS. 6, 7, 10 and 12 to .14 constitute pattern weft yarns, but which might just as well be ground weft yarns, are each to be inserted into two hooks 21 and 21a of the two transport chains 1 and 2, which hooks face each other in a line extending at least approximately at right angles to the transport chains. Slide 7, accordingly, must be displaced by a corresponding amount in the direction toward the stitch forming point before the weft yarn laying device 3 running toward one of the two transport chains .1 and 2 passes over the respective transport chain 1 or 2. Slide 7 thus lags behind the two transport chains 1 and 2 alternately, for example until it has caught up with hook 21a of the chain 2, the hook 210 being opposite hook 21 of the other chain 1. This lagging of slide 7 occurs by means of springs 16, which for this purpose are released accordingly by cam plate 19. When the weft yarn laying device 3 has passed over the respective transport chain 1 or 2, cam plate 19 pulls slide 7 back again by means of lever 18 before the weft yarn laying device 3 starts its movement in the opposite direction.

In the case of FIG. 2, slide 7 is driven positively in a direction parallel to the transport chains 1 and 2 in both directions, namely by means of two endless chains 22 and 23, which are co-directional. The drive thereof again occurs from the toothed wheel 20, to which a sprocket 24 is rotationally connected, the sprocket 24 by means of a chain and another sprocket driving a shaft 25. From the latter is derived the drive of a second shaft 26, which in turn drives a third shaft 27. By means of shaft 25 there is set in motion the endless chain 23, and by shaft 27, the endless chain 22. Each of the two chains 22 and 23 has a respective finger 28 and 28 secured to it and these engage in the slot of respective upright link rods 29 and 30. At their lower ends the link rods 29 and 30 are provided with guide lugs and are fitted therewith on horizontal guide bars 31 and 32 which are directed parallel to the transport chains 1 and 2. In this case the cross bar 14 is rigidly connected to the lower free end of the link rods 29 and 30. When the two endless chains 22 and 23 are driven in the direction of the arrows of FIG. 2, lower reversing wheels 33 and 33 move slide 7 toward the stitch forming point, and the upper reversing wheels 34 and 34' pull slide 7 back to its starting position.

In the embodiments of FIGS. 1 and 2, the cross-bar 14 is movable back and forth parallel to itself. It is feasible also, however, to pivot the cross-bar 14, for movement of the slide 7 crosswise to its fundamental movement, aboutan upright axis at the longitudinal center of the cross-bar 14. According to FIG. 3, this upright pivot axis is an imaginary one. Cross-bar 14 is guided for this purpose at its ends in two crossheads 57 and 57', for which guide bars 31 and 32 are provided. For the pivotal drive of the cross bar 14 there serves a double lever 58 which has a fixed bearing point 59 in the middle between the two transport chains 1 and 2. Each of cables 17 is connected, at one end, to a respective end of the double lever 58. The other end of each cable 17 is connected to fixed supporting structure with an extension spring 16 for each. The crossheads 57 are coupled to the cables 17 and execute by means of the double lever 58 opposite movements. The pivoting of the cross-bar 14 in one direction of rotation is effected by means of lever 18, which cooperates with the cam plate 19, and in the other direction by means of the extension spring 16. There is rotatably fitted on the crossbar 14 a sleeve 60 with a downwardly directed pin 61 which engages in a bearing 62.

The latter is located on the eyelet strip 12. Elements 63 serve to guide the cross-bar 14 at its free ends.

In the case of FIG. 4, the cross bar 14 is likewise pivotable about an upright axis or shaft 64, but a physical one. A yoke 65 is connected to a holder 66 for the cross-bar 14 extending in the direction of the latter. At its lower end, shaft 64 is fitted in a fixed bearing 67. Cross-bar 14 is guided at each end between a respective pair of bars 68 and 68', which are directed parallel to the endless transport chains 1 and 2. Also in this case the cross-bar 14 passes through a sleeve 60, which is rotatably arranged at the eyelet strip 12. The pivotal drive of the crossbar 14 about the axis or shaft 64 occurs at a point of yoke 65 eccentric thereto, the drive system being a hydraulic one, but which could alternatively be a pneumatic one. According to FIG. 5, the drive system includes a double acting piston 69, the rod 70 of which is articulated at one end to the yoke 65 (FIG. 4). To the cylinder of piston 69 two lines 71 and 72 are connected which originate from a control valve 73. The control piston thereof is displaceable by means of two electromagnets 74 and 75. The latter are connected to the limit switches 76 and 77 which are actuated alternately, for example directly by the plate 5 of the weft yarn laying device 3. The feed of this drive device is by means of a pump 78, which takes the pressure fluid from a tank 79. In the feed line 80, a pressure limiting valve 81 is provided.

If it is intended to produce a weft-warp knit fabric which according to German Pat. No. 1,059,608 has a ground material consisting of weft yarns 36 directed obliquely to the longitudinal axis of the fabric, and which is moreover provided with pattern weft yarns 13 which at variance with the weft yarns 36 of the ground material extend parallel to the stitch rows and hence at right angles to the longitudinal axis of the fabric, then at least two weft yarn laying devices are provided, as is evident for example from FIG. 7. In this case, the weft yarn laying device 3 is provided for the pattern-forming weft yarns 13, while the weft yarn laying device 35 is provided for the weft yarns 36 forming the ground material (FIGS. 7, 13 and 14). The weft yarn laying device 35 is movable only crosswise to the transport chains 1 and 2, driven by means of chain 37 and guided at the cross bars 38. The weft yarn laying device 3 has again a slide 7 (FIGS. 8 and 9) which is provided with an eyelet strip 12 (FIG. 7). For the slide 7 the weft yarn laying device 35 has a guide 39 extending parallel to the transport chains 1 and 2 (FIGS. 8 and 9). A spring 40 (FIG. 8) holds slide 7 in the end position away from the stitch forming point of the machine. Slide 7 is provided with a roll 41, which cooperates for example with two cam means that can be actuated alternately. According to FIG. 7, these cam means consist of two guide rails 42 and 43 directed obliquely to the transport chains 1 and 2. The rails 42 and 43 are each pivotable about its end nearer the edge of the fabric and held by a spring 44 or 44' at a respective abutment 45 or 45', which limits the operative position of the guide rails 42 and 43. Upon movement of the two weft yarn laying devices 3 and 35, for example toward the transport chain 1, roll 41 will in due time make contact with the side of the guide rail 42 toward the stitch-forming point of the machine, so that the rail 42 presses slide 7 of the weft yarn laying device 3 forward. A guide portion 46 or 47 directed at right angles to the transport chains 1 and 2 is contiguous with the guide rails 42 and 43, respectively. When roll 41 has passed the guide portion 46 associated with guide rail 42, slide 7 snaps back under the action of spring 40, and with the reversal of movement of the weft yarn laying devices 3 and 35, roll 41 of slide 7 pivots the guide rail 42 forward. The guide rails 42 and 43 therefore function as railroad type switches.

In the case of FIGS. 7 to 9, the weft yarn laying device 3 for the pattern weft yarns 13 receives its fundamental movement directly from the weft yarn laying device 35, which lays the ground weft yarns 36. As opposed thereto, according to FIG. 10 only the weft yarn laying device 35 for the oblique ground weft yarns 36 is driven by means of chain 37, while the weft yarn laying device 3 for the patterning weft yarns 13 is driven by means of its own chain 46. Although both chains 37 and 46 have a common main drive 47, chain 46 is preceded by a transmission gear 48. It is evident from FIG. 11 that in this case the weft yarn laying device 3 has a single end plate 51 guided by bars 49 and rolls 50, the plate 51 having at the top a fixed eyelet strip 52 and at the bottom the eyelet strip 12, the latter being located at the slide 7. For the latter, cheek 51 is provided with two guide pins 53 and 53' which extend in the direction of the transport chains 1 and 2. On one of these is again fitted a spring 40, which holds slide 7 in the rear end position. Also slide 7 is again provided with a roll 41, which, however, alternately cooperates with two wedges 54 and 55 (FIGS. and-11). The wedges 54 and 55 are alternately lifted and lowered into the path of roll 41 and hence act in principle on slide 7 exactly like the guide rails 42 and 43 of FIG. 7.

In the case of FIG. 7, the pattern weft yarn laying device 3 is located in front of the ground weft yarn laying device 35. The pattern weft yarns 13 then lie on the front (right side) of the textile fabric and are, as can be seen from FIG. 14, bound in between the ground weft yarns 36 and the sinker stitches 81 of the warp knit fabric. Alternatively, however, the pattern weft yarn laying device may be arranged behind the ground weft yarn laying device 35. In this case, the pattern weft yarns 13 will then be on the back of the textile fabric and are bound in between the needle stitches 56 of the warp knit fabric and the ground weft yarns 36, as is evident from FIG. 13.

As shown in FIG. 12, the ground weft yarn laying device 35 may be provided with a pattern weft yarn laying device 3 before it as well as with a second pattern weft yarn laying device 82 behind it, which then guides the pattern weft yarns 83. In this way a textile fabric can be produced which exhibits pattern weft yarns on both sides, which in the case of a warp knit fabric are bound in, in the sense of FIGS. 13 and 14.

If a weft-warp knit fabric is to be produced in which the ground material consists of weft yarns which extend parallel to the stitch rows, then the weft yarns 13 are the ground weft yarns and hence replace the obliquely directed weft yarns 36 of FIG. 3, l3 and 14. The weft yarn laying device 3 would thus guide the ground weft yarns and would then of course have to be of the size of the weft yarn laying device 35.

What is claimed is:

l. A flat warp knitting machine comprising two continuously driven endless transport chains provided with hooks, carrier means, weft yarn laying means carried by the carrier means, means for moving the carrier means and therewith the weft yarn laying means back and forth transversely to'the transport chains for inserting weft yarns alternately into the hooks of the two transport chains and means for reciprocating the weft yarn laying means relative to the carrier means in the direction of motion of the transport chains for the insertion of the weft yarns into at least approximately opposite pairs of hooks so that the weft yarns extend at least approximately at right angles to the transport chains.

2. Flat warp knitting machine according to claim 1, further comprising guide rails each directed obliquely to the transport chains and pivotably mounted at its outer end, means defining an abutment adjacent each of the rails and means resiliently urging each of the rails against the abutment means adjacent thereto.

3. Flat warp knitting machine according to claim 1, further comprising two wedge pieces and means for alternately lifting the wedge pieces into the path of the weft yarn laying device.

4. Flat warp knitting machine according to claim 1, in which the weft yarn laying means comprises a cross slide and weft yarn guide means carried by the cross slide and the cross slide is carried by the carrier means for said reciprocating by said reciprocating means.

5. Flat warp knitting machine according to claim 4, in which the reciprocating means comprises a cross-bar by means of which the cross slide is movable in said reciprocation.

6. Flat warp knitting machine according to claim 5, in which the reciprocating means further comprises means for driving the cross-bar back and forth parallel to itself.

7. Flat warp knitting machine according to claim 6, further comprising two co-directional drive means operatively connected to the respective ends of the cross-bar.

8. Flat warp knitting machine according to claim 5, further comprising means pivoting the cross-bar at the longitudinal center of the cross-bar.

9. Flat warp knitting machine according to claim 8, further comprising a sleeve pivotably mounted on the cross-slide, the cross-bar being carried by the sleeve.

10. Flat warp knitting machine according to claim 9, further comprising two cross-heads, the cross-bar being mounted near its respective ends in the respective cross-heads, a pair of guide bars parallel to the transport chains, the guide bars carrying the respective cross-heads for movement along the guide bars, and means for driving the cross-heads in opposite directions. I

11. Flat warp knitting machine according to claim 10, in which said driving means comprises means defining a double lever mounted for pivotal movement about a point intermediate its ends, means for pivotally moving said lever means in alternatingly opposite senses and means for transmitting movement from the respective ends of the lever means to the respective cross-heads.

12. Flat warp knitting machine according to claim 9, further comprising means connected to the cross-bar at opposite sides of the cross-slide, pivot means supporting said connecting means for pivoting about an axis parallel to the axis of pivoting of the sleeve, and means for oscillatingly driving the pivot means.

13. Flat warp knitting machine according to claim 1, in which the reciprocating means includes a cam and means operatively connecting the cam to the weft yarn laying means, the connecting means including spring means for effecting a return movement of the weft yarn laying means.

14. Flat warp knitting machine according to claim 1 in which the reciprocating means includes a pair of endless chains.

15. Flat warp knitting machine according to claim 1, in which the reciprocating means includes drive means comprising a double acting hydraulic or pneumatic piston.

16. Flat warp knitting machine according to claim 15, further comprising a second weft yarn laying means and means for moving the second weft yarn laying means back and forth transversely to the transport chains but not in the direction of movement of the transport chains.

17. Flat warp knitting machine according to claim 5, further comprising means for guiding the cross slide along the length of the cross-bar while the weft yarn laying means moves back and forth transversely to the transport chains. 

1. A flat warp knitting machine comprising two continuously driven endless transport chains provided with hooks, carrier means, weft yarn laying means carried by the carrier means, means for moving the carrier means and therewith the weft yarn laying means back and forth transversely to the transport chains for inserting weft yarns alternately into the hooks of the two transport chains and means for reciprocating the weft yarn laying means relative to the carrier means in the direction of motion of the transport chains for the insertion of the weft yarns into at least approximately opposite pairs of hooks so that the weft yarns extend at least approximately at right angles to the transport chains.
 2. Flat warp knitting machine according to claim 1, further comprising guide rails each directed obliquely to the transport chains and pivotably mounted at its outer end, means defining an abutment adjacent each of the rails and means resiliently urging each of the rails against the abutment means adjacent thereto.
 3. Flat warp knitting machine according to claim 1, further comprising two wedge pieces and means for alternately lifting the wedge pieces into the path of the weft yarn laying device.
 4. Flat warp knitting machine according to claim 1, in which the weft yarn laying means comprises a cross slide and weft yarn guide means carried by the cross slide and the cross slide is carried by the carrier means for said reciprocating by said reciprocating means.
 5. Flat warp knitting machine according to claim 4, in which the reciprocating means comprises a cross-bar by means of which the cross slide is movable in said reciprocation.
 6. Flat warp knitting machine according to claim 5, in which the reciprocating means further comprises means for driving the cross-bar back and forth parallel to itself.
 7. Flat warp knitting machine according to claim 6, further comprising two co-directional drive means operatively connected to the respective ends of the cross-bar.
 8. Flat warp knitting machine according to claim 5, further comprising means pivoting the cross-bar at the longitudinal center of the cross-bar.
 9. Flat warp knitting machine according to claim 8, further comprising a sleeve pivotably mounted on the cross-slide, the cross-bar being carried by the sleeve.
 10. Flat warp knitting machine according to claim 9, further comprising two cross-heads, the cross-bar being mounted near its respective ends in the respective cross-heads, a pair of guide bars parallel to the transport chains, the guide bars carrying the respective cross-heads for movement along the guide bars, and means for driving the cross-heads in opposite directions.
 11. Flat warp knitting machine according to claim 10, in which said driving means comprises means defining a double lever mounted for pivotal movement about a point intermediate its ends, means for pivotally moving said lever means in alternatingly opposite senses and means for transmitting movement from the respective ends of the lever means to the respective cross-heads.
 12. Flat warp knitting machine according to claim 9, further comprising means connected to the cross-bar at opposite sides of the cross-slide, pivot means supporting said connecting means for pivoting about an axis parallel to the axis of pivoting of the sleeve, and means for oscillatingly driving the pivot means.
 13. Flat warp knitting machine according to claim 1, in which the reciprocating means includes a cam and means operatively connecting the cam to the weft yarn laying means, the connecting means including spring means for effecting a return movement of the weft yarn laying means.
 14. Flat warp knitting machine according to claim 1, in which the reciprocating means includes a pair of endless chains.
 15. Flat warp knitting machine according to claim 1, in which the reciprocating means includes drive means comprising a double acting hydraulic or pneumatic piston.
 16. Flat warp knitting machine according to claim 15, further comprising a second weft yarn laying means and means for moving the second weft yarn laying means back and forth transversely to the transport chains but not in the direction of movement of the transport chains.
 17. Flat warp knitting machine according to claim 5, further comprising means for guiding the cross slide along the length of the cross-bar while the weft yarn laying means moves back and forth transversely to the transport chains. 